Backyard Aquaponics
A place to discuss aquaponics

Does any one use ail lift pumps? they seams to be the best off both worlds useing airation to move water. why arent more people useing them?

you seem to need air flow to lift the water - submersible pumps are simply easier to source too.

With my setup, it was easier and cheaper to use a submersible pump.

my system is outside in the weather, so i would have had to build a waterproof box for the blower, which would have cost more to lift it the distance i wanted (my setup is on sloped land)

But i have seen them used, and they cant burn out by pumping air (like submersibles if the float swich doesnt work or exist)

Found this (there does not seem to be all that much out there on airlift systems)

How can I make a simple airlift ?
Place a airstone in the bottom of your tank and position a funnel with a tube extending the funnel stalk over the airstone so that the airbubbles are trapped in the funnel and forced up the stalk. The airbubbles and water mixture will rise up the extension of the funnel stalk. If the top end of the funnels stalk is above the water level the air-bubble and water mixture will rise above the water level.

The extension to the funnel stalk should have a ratio of 1 : 50 internal diameter of tube to length of tube. The maximum lift will be half the submerged length of the tube.

And this too:

An airlift pump is not a pump in the strictest sense because it does not significantly alter the pressure or velocity head of the fluid in any practical degree. Air or other gas is delivered at the bottom of the lift pipe and mixes with the liquid. The air-liquid mixture, with lower specific weight than the liquid, rises in the pipe and is discharged at the point above the level of the liquid. This device can be used for elevating liquids that contain foreign materials or are corrosive. Twenty to 40% of the energy used to compress the gas is effective in elevating the liquid.

Wondering if a air compressor (the kind for a paint gun) would be enough too move water 6 feet above water level.

In using a compressor many systems could be attached on to the one air source.

I am thinking just a 1/2 inch pipe with a T joint. And to have the air intake perpendicular to the water flow

“40% of the energy used to compress the gas is effective in elevating the liquid.”

Hummmmmmm that does not sound too effective but with all the extra aeration that should increase the stocking density of fish, greatly.

I can’t foresee anything wrong with using air lift pump and I am looking into the project more as I have a air compressor lying around doing nothing I will keep you guys posted with what I am doing.

Does any one have any suggestions? Comments? Any Info would be greatly appreciated.

I have used air lift in the past for hydroponics. I didn't need much lift , and used an aquarium pump. I see no reason why this could not be applied to aquaponics.

http://www.backyardaquaponics.com/forum ... pic_id=105

from what I understand lots of fine bubbles will work better than a bunch of big bubbles...

C-G, in relation to your 6 feet lift, i think the relation ship is with diameter and submerged length. More bubble will probably only flow more water, not to a bigger height, but i read up on this a long time ago, i'm far from an expert

I did manage 6 feet, using an aquarium air pump and fairly small bore black retic pipe. But the flow rate was very slow. I still managed to grow a wall full of cherry tomatoes using the system though! I had nft channels hanging on the wall but had to supplement airation in the the hot weather by putting an airstone in the channels. I used a mix of cow manure, sheep manure and wood ash to make uo the hydroponic solution.

BTW, I found that the more submerged length, the better height you can reach with a small air pump.

The tomatoes tasted great!

Sounds like a good idea (also you'd have some backup capacity if the power went off for a short while). Only potential problems I can think of are:

(1) With compressors is there any oil or lubricant in the air?
(2) What would be the life expectancy of the compressor, since it'd be going on and off quite frequently?
(3) Would the compressor actually use more power than a similar air pump and hence cost more?
(4) How would you reduce the air flow so the compressor didn't have to run all the time?

Aside from the above; sound like a good idea (time to ebay aircompressors :-) .... Yep lots of the and some are cheap)


Ok on the OIL question I found this under and add for an "Oil free compressor"

"Through utilizing oil free technology, not only will you receive cleaner air coming out of the tank through no oil contamination, but it will result in an economically sounder experience with less wastage. With no dirty oil needing to be changed, and without having to inject more oil in, this is the perfect compressor for all levels of experience!"

Anyone have some knowhow on compressors?

Eame0002 these are some really good questions, I never even taught about them.

You have to put oil into a compressor but it’s very little I am not sure now much of this ends up in the air coming out. Maybe a filter for drinking water (2micron) would take out the oil if it a problem.

Compressors are made to run for long times it should live a long happy life.

Would the compressor use more energy? This would depend on
1 how often it has to fill up the air tank.
&
2 well that’s all I could think of now, I would like mines to fill up twice a day.

Compressors have a valve that controls the psi coming out of the tank. I am thinking of running the air to a main 1/2 inch PVC pipe with T joints leading to ball valves so I could have more than one outlet for air. The only problem I could for see is that all the valves would be relative to each other. Meaning that if I open one valve I would increase the air flow through the said valve while decreasing the air flow through the others

Let me know how it goes, I'm particularly interested in how often the compressor has to kick in. What sort of air flow are you looking at (litres/minute), and for how much tank volume?

You can get moisture traps that fit onto the compressors outlet. Hardware stores should stock them.

My thoughts you will lift more water for your dollar with a pump than compressing air and then trying to lift water